Broadband wireless access devices based on 802.16d protocols may be used in a wide variety of application scenarios. One of the scenarios is that an SS accesses a predetermined BS according to network planning. One advantage of such an access approach is that the devices are relatively simple to be developed and managed, and in addition, because the SS only accesses the predetermined BS, configuration information of the SS such as QoS policy can be configured in the BS, so that different QoS configurations of different SSs can be managed conveniently.
If an SS accesses a predetermined BS, configuration information of the SS, such as all QoS policy and information for judging SS subordination, can be configured in the BS statically. In such a case, if the SS attempts to access another BS, because the BS is unable to find the configuration information of the SS, it rejects the access of the SS. Consequently, the SS can access a network if the SS accesses a BS that stores the configuration information of the SS. It can be seen that the above access approach can work normally in any area that is covered by a single BS. If the SS is in an overlap area between two or more BSs, however, the SS may be unable to access the network within a long time.
As shown in FIG. 1, an SS is in the overlap area between two base stations BS1 and BS2, and the configuration information of the SS is configured in the BS1. The SS, if starting up during a certain time period when a signal from the BS2 is strong, may scan the signal and access the BS2. When the BS2 checks and finds out that no configuration information of the SS is available, it does not establish a service connection for the SS. In addition, because the BS2 has no mechanism to notify the SS to terminate its connection to the BS2 and make another attempt to connect to the BS1, the SS is hung on the BS2. In other words, the SS is unable to access the network and unable to exit from the BS2.